vue-cli-service build does not update or invalidate node_modules/.cache, resulting in broken build

Version

3.0.1

Node and OS info

node v8.9.3 / npm 6.4.1 / Windows 10

Steps to reproduce

I have the app A which has dependency B. A uses B’s sources, thus B is in vue.config.js as transpiled:

transpileDependencies: ["B"]

• in A: vue-cli-service build --modern builds app and creates node_modules/.cache
• in B: change code, increase version, and publish it to npm repo
• in A: change B’s version in package.json
• in A: npm update B, which updates node_modules/B
• in A: increase version
• in A: vue-cli-service build --modern

What is expected?

A/dist should correspond to A’s and B’s sources.

What is actually happening?

A/dist is the same (same hashes, same content), as in the previous build

---

If I manually delete node_modules/.cache, and run the build again, then it works - the dist content corresponds to the sources.

[marosivanco]

Workaround: npm install rimraf --save-dev

In package.json add the prebuild script:

...
"prebuild": "node ./node_modules/rimraf/bin.js ./node_modules/.cache",
"build": "vue-cli-service build --modern",
..

Kind of clumsy, but better than corrupted build.

[LinusBorg]

“There are two hard problems in programming: naming things, and caching.”

What options do we have?

• We could add package.json’s dependencies, devDependencies and peerDependencies fields as inputs to the chache-key generating code (e.g. here. But that wouldn’t work for updated nested dependencies (i.e. clearing yarn.lock and reinstalling, adding updated dependencies in the process
• We could add a postinstall script that purges the cache whenever anything is installed into the project (is that possible?)
• We could document this, and add a command/flag to easily purge the cache manually (vue-cli-service build --clearCache or something).

Other ideas? @sodatea